Drafting device



MV l i941- v H. A. DIBBLE, .JR 2,247,362

DRAFTING DEVICE Filed Sept. 15. 1959 Patented July '1; 1941 UNITED STATES PATENT OFFICE DRAF'HNG DEVICE Howard A. Dibble, dr., Hartford, Conn. Application September l5, i939, Serial No. 295,121

3 Claims.

My invention relates to drafting devices.

It has among its objects to provide an improved drafting device, and one especially adapted to use in drawing screws or screw threads, whereby the work of the draftsman is facilitated and expedited. A further object of my invention is to provide an improved drawing implement adapted to be used in connection with a T-square and of an improved construction adapted to engage a T-square in such manner that the device may be used 1n diierent relations with the T- square in such manner as to adapt it very conveniently to use on a wide range of work. A fur-n ther object of my invention is to provide an improved draiting guide wherein, while obtaining the above advantages, it is made possible to produce a device which not only is adapted to provide a draitsman, with a guide for any angle usually required in his work, but which further is adapted to be readily disposed in any desired relation with a iF-square, while also being of such construction that complete accuracy is obtainable over long periods of use irrespective oi wear. These and other objects and advantages oi my construction will, however, hereinafter more fully appear.

In the accompanying drawing, I have shown for purposes or illustration, one embodiment which my invention may assume in practice.

In the drawing,

Figure i is a perspective view showing my im proved device in outline and in use on a drawing board;

Fig. 2 is an enlarged detail top plan view of the device illustrated, and

Fig. 3 is an end elevation thereof.

In this illustrative construction, I have shown my improved guide member, generally indicated at l, in use on a drawing board 2 and in connection with a T-square d thereon, the device i being shown in Figure l in a position exposing a drawing it on a sheet d attached to the board i; this device i being of an improved construction as hereinafter described.

My improved guide member l is generally rectangular in form and herein in the form ci a square provided at each corner with a right angled corner including elongated surfaces d of substantial length and extending away from the corner. Herein, these surfaces t on each side of the device i are indented by angularly disposed cut-out portions, generally indicated at l, t, d and i0. Of these, the cut-out portion i has straight sides or edges ii disposed at an angle of 90 to each other in such manner that each Vparsed at an angle of clination from the edge il is at an angle of 45 to the vertical and a angle is included therebetween. The cutout portion 0 herein includes edges li eachdisto the vertical and in such manner as to include an angle of therebetween. The cut-out portion 0 also has its edges it disposed at an angle of 30 to the vertical in such manner as to include an angle oi 60 therebetween, while the cut-out portion i0 has its edges it at an angle of 15 to the vertical in such manner as to include an angle of 30 therebee tween. Further, it will be noted that these cutout portions l, t, 0 and i0 are each disposed centrally of the side of the member t in which the cut-out portion is disposed, with all their vertices passing through a single central point which is the center oi the device i. It will iurther be noted that each edge of each cut-out portion is suitably marked, one edge bearing a legend indicating the number of degrees oi invertical, while a .suitable legend indicating the number of degrees included is disposed along the other edge. Also, it will be understood that, if desired, a graduated or rule mrtion lb may be provided along the several edges d, i. e. around the portions of the periphery of the member i formed by these edges d, and also on the various edges it, it, t3, itl, or on any selected edges of either set oi edges, although to facilitate illustration I have herein only shown such graduations along the edges 0 and Mi, i. e. adjacent the cut-out portion l0. Attention is also directed to the iact that my improved construction having the four corners makes it possible to provide, if desired, a series of circular openings le of different graduated diameter ex tending across the same between diagonal corn ners in such manner as to be readily useable, while it also makes it possible to use a like series of hexagonal openings ii of diderent sizes, lilrel1 wise disposed between diagonally opposite corners and herein transversely with respect to the series of circular openings it.

As aresult of my improved construction, it is made possible to cause any set oi' spaced edges t along any side of the member Il to engage with the T-square, at the same time that complete accuracy of positioning of the member t relative to the T-square is assured. Fur-ther, it will be observed that the elongated edges t are long wearing, there being no points to wear down'in service. Moreover, the member l is oi such conformation and size that' it may be readily spun about 'in the fingers by the draftsman in order to present the edges oi any desired cut-out por- 'that the invention may tion to the work being done. Further. the cut-out portions 1, 8, 9 and l0 are symmetrical so that T-square remaining stationary the de vice I may be disposed with any side edge thereof in contact with the T-square without displacing the center line of the device. Similarly, in isometric work, the device may be turned to present any selected angle thereon without requiring recenterlng o! the device by movement of the T- square, the line intercepting the vertices of the angles on the vertically disposed edges always being equidistant from the T-square. Thus, when a different angle is required, Ithe drai'tsman by a simple movement of the member i. can readily bring the desired edges il, i2, i3l or ld into the proper relation to the work. Similarly, the various circular openings i8, or hexagonal openings i1, may be readily utilized in widely diierent positions by merely sliding the member l in reverse directions along the T-square. While the size of the device i may be varied, in ordinary practice, the same need be only approximately lve inches square and be made of Celluloid or suitable material, in such manner as to enable the complete device to be readily and inexpensively produced. These and other advantages of my improvements will, however, be apparent to those skilled in the art While I have in this application specifically dey scribed one embodiment which my invention may assume in practice, it will be understood that the same is shown for purposes of illustration, and be modified and embodied in various-other forms without departing from its spirit or the scope of the appended claims.

What I claim as' new and desire to secure by Letters Patent is: 1. A drafting .device having a generally rectangular body including four protruding corner tangular body including i'our portions the sides of which if projected would form a rectangle and also having an angular indentation in each edge between and denning said corner portions, each of saidindentations having oppositely inclined edges forming -a different included angle and each angle having the oppositely inclined edges thereof of equal length.

2. A- drafting device having a generally rectangular body including four protruding corner portions the sides of which if projected would form a rectangle and also having an angular indentation in each side edge between and dening said corner portions, each ot said indentatlons having oppositely inclined edges forming a dinerent included angle and each angle having the oppositely inclined edges thereof of equal length, said indentations being symmetrically disposed in the side edges oi' said body with the apexes of all indentations disposed in lines passing at right angles through a common point at the center oi' said body.

3. A drafting device having a generally recprotruding corner portions the sides f which if projected would form a rectangle and also having an angular indentation in each side edge between and dening said corner portions, each of said indentations having oppositely inclined edges forming a diderent included angle and each angle having the oppositely inclined edges thereof of equal length, and a plurality of relatively transversely disposed series of openings providing aids in drafting and each aligned in said body between diagonally opposite corners, one of said series comprising hexagonal openings having opposite dat sides thereof arranged parallel to opposite parallel side edges of said body.

HOWARD A. DIBBLE, Jil. 

